吕宋海峡夏季内潮数值模拟

Numerical Simulations of Internal Tides in the Luzon Strait in Summer

利用三维海洋环流模式MITgcm,对吕宋海峡夏季内潮的生成与传播进行了分析。结果表明,在八分潮驱动的情况下,吕宋海峡夏季生成的内潮能量有4.7GW传入西太平洋,7.7GW传入南海,其中M2分潮最强,K1分潮次之。半日分潮主要在恒春海脊中部和巴坦群岛附近生成,并在传播过程中衰减迅速;全日分潮主要在巴布延群岛西北处及兰屿海脊北部生成,在传播过程中衰减较慢。西传M2和K1内潮主要在兰屿海脊南部生成,且西传M2内潮在恒春海脊北部得到增强,在恒春海脊中部则被削弱。在恒春海脊北部生成的东传M2和K1内潮在经过兰屿海脊时被削弱。恒春海脊使得部分源于兰屿海脊的西北向全日内潮转向西南,形成向南海海盆的内潮分支。

In this paper,the spatial-temporal characteristics and energetics of the internal tides in the Luzon Strait in summer is investigated using a fully nonlinear nonhydrostatic three-dimensional model（MITgcm）driven by eight principal tidal constituents together.There is 4.7GW internal tide energy propagating into Pacific while 7.7GW into South China Sea.M2 internal tide is the most intensive component,and K1 internal tide is the second.The influences of the two ridges to the generation of the internal tides are further clarified.The semidiurnal internal tide which dissipate sharply during its propagation mainly generated in the southwest of Batan islands and the middle part of the Hengchun Ridge,while the diurnal internal tide which dissipate moderately mainly generated in the northwest of Babuyan islands and the northern part of the Lanyu Ridge.The Lanyu Ridge is the main source of western propagating M2 and K1internal tides,which is also a block to the southeastern propagating M2 and K1tides generated in northern part of the Hengchun Ridge.The western propagating M2 internal tide generated in the Lanyu Ridge is enhanced and reduced through northern and middle part of the Hengchun Ridge.When the northwestern propagating diurnal tides generated in the Lanyu Ridge flow over the Hengchun Ridge,part of them turns to southwest,which is the branch of internal tide that flows into the South Sea Basin.